Minor updates to doc

- Add section for fetch specific item ref
- Add example for withValues(false) for search
Review changes
Merge pull request #63 from orchestrate-io/jde-minor-docs

Minor updates to doc
Partial update support (JsonPatch and JsonMergePatch)

- onPatch and JsonMergePatch for KV and Events
- Event Update (with conditional)
- Event Purge (with conditional)
- Get individual event
- Deprecate .put for create, in favor of a new .create
- Improved error handling
- Some perf tweaks (ie rawValue is lazily created)
Fix serialization warnings
Merge pull request #64 from orchestrate-io/jde-partial-updates

Partial Updates
Update download information for Java client release.
Update README and set new development version.
Fix warnings in javadocs with Java 8.
added aggregate functions to the api
added an integration test
use a builder pattern to add aggregates to the query
refactored the aggregate builder methods into their own class
added some aggregate examples to the 'querying' docs
touch-ups to the javadocs
refactored the builder a little bit, to match the JsonPatch.builder(), and added more javadoc
updated www docs to match refactored Aggregate builder
more javadocs... also fixed a few typos...
Changes from code review.